Nebraska tribe or city (5)
I believe the answer is:
omaha
This clue is a double definition.
'nebraska tribe' is the first definition.
(I've seen this in another clue)
'city' is the second definition.
(Omaha is an example)
(Other definitions for omaha that I've seen before include "Nebraska's largest city" , "US city; D-Day 16" , "Where American may work" , "American-Indians" , "Largest city in Nebraska" .)